Function win 

fn win(
    winners: &mut BTreeMap<String, (Option<String>, u64, String)>,
    theirs_now: &mut Vec<(String, String)>,
    computer: &str,
    key: String,
    change: (Option<String>, u64, String),
)

A change read in as the winner of its entry. The content of a file sealed apart that another device’s change named, and that this one passes, noted as theirs (theirs_now, Sealed::theirs).